Positioning device

Abstract

The invention relates to a positioning device, comprising a housing (1) with a guide device (2) and an actuator (3) which is mounted so as to be linearly movable within the housing (1) and which is laterally enclosed by an annular seal (2.1) of the guide device (2). According to the invention, the annular seal (2.1) is made of a polyurethane.

Description

[0001] Positioning device

[0002] The invention relates to a positioning device according to the preamble of claim 1.

[0003] A positioning device of the type mentioned above is known from patent document DE 10 2022 122 108 B3. This positioning device consists of a housing with a guide element and an actuator mounted linearly movable in the housing and laterally enclosed by a ring seal of the guide element (see Figure 2 therein).

[0004] The invention is based on the objective of improving a positioning device of the type mentioned at the outset. In particular, a positioning device is to be created in which the actuator is held in its current position better than before, for example in the event of a pressure or power failure.

[0005] 20

[0006] This problem is solved with a positioning device of the type mentioned at the outset by the features described in the characterizing portion of claim 1.

[0007] According to the invention, the ring seal 25 is therefore made of polyurethane.

[0008] In other words, the positioning device according to the invention is characterized by the fact that the ring seal is no longer made of rubber, as in the prior art mentioned above, but now of polyurethane. As tests have shown, polyurethane possesses the surprising property that, on the one hand, it provides high static friction when the actuator is stationary, while on the other hand, it offers only low sliding friction when the actuator is moving. Thus, polyurethane optimally fulfills the boundary conditions given in the present application, namely that the actuator must be easily movable while, for example, being able to maintain its position in the event of a pressure or power failure.

[0009] 10

[0010] Other advantageous embodiments of the positioning device according to the invention are set out in the dependent claims.

[0011] The positioning device according to the invention, including its advantageous further developments according to the dependent claims, is explained in more detail below with reference to the graphic representation of a preferred embodiment.

[0012] It shows 20

[0013] Figure 1 shows a section of the positioning device according to the invention with two ring seals; and

[0014] Figure 2 shows a side view of the positioning device according to Figure 1, rotated by 90° (to the left). 25

[0015] The positioning device shown in the figures, which in this case is designed as a so-called preferably pneumatically operated pin-pulling cylinder, consists of a housing 1 with a guide element 2 and an actuating element 3 that is linearly movable within the housing 1 and laterally enclosed by a ring seal 2 of the guide element 2. It is preferably (but not necessarily) provided, as shown, that the guide element 2 is designed as a separate component. Furthermore, it is preferably provided that the guide element 5, which is preferably bushing-shaped, is pressed into the housing 1. It is also preferably provided that the actuating element 3 is designed as a piston rod (preferably of a pneumatically operated actuating cylinder).

[0016] 10. In more detail, it is particularly preferred that the guide device 2 for receiving the actuator 3 has a cylindrical inner wall 2.2. Accordingly, it is preferred that at least one section of the actuator 3 guided by the guide device 2 is cylindrical. Furthermore, a groove for receiving the ring seal 2.1 is preferably provided on the inner wall 2.2 of the guide device 2.

[0017] Essential to the solution according to the invention is that the 20 ring seal 2.1 is made of a polyurethane. A polyurethane with a hardness of at least 92 Shore A is particularly preferred (see also https: / / de.wikipedia.org / w / index.php?title=Polyurethane&oldid=244152570). As an example, the material P5008 from Parker Hannifin GmbH, marketed under the brand name Ultrathan®, may be mentioned here; it has higher heat resistance and lower compression set compared to commercially available polyurethane grades.

[0018] 30 As can be seen from Figure 1, it is particularly preferred that the ring seal 2.1 is designed as an O-ring (see also https: / / de.wikipedia.Org / w / index.php? title=0-Ring&oldid=242500701 ), i.e. in particular that it consists of a torus-shaped, elastic body.

[0019] To ensure good axial guidance of the actuator 3, 5, as shown in Figure 1, it is preferably provided that a total of two, preferably identical, ring seals 2.1 are arranged on the guide device 2. The (two) ring seals 2.1 are preferably arranged one behind the other in the longitudinal direction of the actuator 3. The distance 10 between the two ring seals 2.1 is preferably more than 5 mm. However, more than two ring seals 2.1 can also be provided, for example, at least three, preferably four, or even more.

[0020] 15 Finally, to reduce wear, it is particularly preferred that the ring seal 2.1 arranged between the guide device 2 and the actuator 3 is designed to define a gap 4 between the guide device 2 and the actuator 3. 20

[0021] Reference symbol list

[0022] 1 case

[0023] 2 Guide system

[0024] 2.1 Ring seal

[0025] 2.2 Inner wall

[0026] 3 Actuator

[0027] 4 columns

Claims

Patent claims 1. Positioning device comprising a housing (1) with a guide device (2) and an actuating element (3) mounted linearly movable in the housing (1) and laterally enclosed by a ring seal (2.1) of the guide device (2), characterized in that the ring seal (2.1) is made of polyurethane.

2. Positioning device according to claim 1, characterized in that the ring seal (2.1) is designed as an O-ring.

3. Positioning device according to claim 1 or 2, characterized in that a total of two ring seals (2.1) are arranged on the guide device (2).

4. Positioning device according to claim 3, characterized in that the ring seals (2.1) are arranged one behind the other when viewed in the longitudinal direction of the actuator (3).

5. Positioning device according to claim 3 or 4, characterized in that the distance between the two ring seals (2.1) is more than 5 mm.

6. Positioning device according to one of claims 1 to 5, characterized in that the ring seal (2.1) arranged between the guide device (2) and the actuator (3) is designed to define a gap (4) between the guide device (2) and the actuator (3).

7. Positioning device according to one of claims 1 to 6, characterized in that the guide device (2) for receiving the actuator (3) has a cylindrical inner wall (2.2).

8. Positioning device according to claim 7, characterized in that a groove for receiving the ring seal (2.1) is provided on the inner wall (2.2).

9. Positioning device according to one of claims 1 to 8, characterized in that at least one section of the actuator (3) guided by the guide device (2) is cylindrical.

10. Positioning device according to one of claims 1 to 9, characterized in that the guide device (2) is designed as a separate component.

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